This invention relates to folding machines; and, more particularly, to a mechanism for adjusting the spacing between fold-rollers thereof.
Still more particularly, this invention is an improvement to the radial-roll folder described and claimed in U.S. application Ser. No. 713,323 of Harold E. Boyer and Jerry V. Trisler filed on Aug. 10, 1976.
A preferred form of the invention is embodied in a buckle-type folder. In this respect, a conventional buckle folder is schematically illustrated in FIG. 1 of the drawings. Therein, a fixed roller, or roll, F has five relatively movable or "floating" rollers associated therewith. That is, all of the rollers are journalled in a frame, not shown, but roller a is pivotably adjustable about point 10 by an adjusting means schematically illustrated as 12 in order to adjust a first "nip" space indicated by arrow 1. Roller b is similarly adjustable with respect to the fixed roller F in order to adjust the "nip" space indicated by arrow 2; roller c is adjustable with respect to roller b in order to adjust the nip space indicated by arrow 3; roller d is adjustable with respect to roller c in order to adjust the nip space indicated by arrow 4; and so on.
It should be noted, with respect to the above described conventional folder, that since only roller F is fixed, errors in adjusting subsequent rollers are cumulative.
In operation, when a sheet of paper, such as P in FIG. 1, is to be folded it is fed between the fixed roller and the first roller a until it strikes a stop S in a first fold pan 14. The paper then buckles downwardly as shown at P-2 into the "nip" illustrated by arrow 2 between the fixed roller F and the second movable roller b. The paper is then fed and buckled in seriatim into fold pan 16; between movable rollers b and c; into fold pan 18; between movable rollers c and d; and so on.
From the above description, it can be seen that the sheet P is folded over and over again so that the stock thickness passing between successive rollers gets larger and larger. In this respect, each of the movable rolls b-e is conventionally, separately adjustable by a lever and spring arrangement similar to the structure such as 12 associated with the first movable roller a; and, moreover, each movable roll has a similar lever-spring structure located on each of its ends. Additionally, it should be noted that adjustment of one of the movable rollers such as b, in order to change the nip space indicated by arrow 2, conventionally results in an alteration of a nip space indicated by arrow 3 and so on.
Finally, before turning to the structure of the invention, it should be appreciated that the various rollers are conventionally gear-driven. Since the position of each of the movable rollers is dependent upon another, however, the customary gear train between the rollers cannot satisfactorily drive or be driven on their "pitch diameters." Hence, not only is there a resulting loss in efficiency, but the gears run quite noisily; and, the drive-power requirements become disproportionately larger with each additional movable roller that is added to the train.
The above mentioned application to Boyer and Trisler states that it is a fundamental purpose of their invention to provide an improved roller adjusting mechanism for a folding machine wherein it is not necessary to manually adjust individual rollers. A folding machine built in accordance with their invention, however, must be manually reset before it can be automatically adjusted. Thus, it is an object of this invention to provide a folding machine as described by Boyer and Trisler which can be automatically reset.
Another difficulty with the Boyer/Trisler machine claimed in the other application is that the adjustable rollers, once they find their proper set positions, have to be manually locked therein. Thus, it is another object of this invention to provide an automated folding machine of the type described above wherein adjustable rollers can be automatically locked in their appropriate positions without the manual intervention of an operator.
Yet another difficulty with the folding machine described in the above mentioned Boyer/Trisler application is that as the adjustable rollers are being set, before they are locked, their positions are not positively fixed. That is, they can jiggle out of the proper positions. Therefore, it is another object of this invention to provide a folding machine of the type described above having a mechanism which positively holds the adjustable rollers in their proper positions until they are locked.